The objective is to understand how children with type 1 diabetes and parents (together with health-care providers) manage diabetes across adolescence to cultivate the child's competence and diabetes adjustment and meet autonomy needs. We explore how it is not only the amount of behavioral involvement of parents (i.e., parents performing diabetes tasks), but the child's appraisal of the form of that involvement, that influences whether adolescents are successful in their diabetes adjustment. The proposed research utilizes a transactional developmental model to examine behavioral and appraised parental involvement and diabetes adjustment both longitudinally across the transition into adolescence and daily. The major aims are to examine (a) developmental changes in mother's behavioral involvement as a function of child age, pubertal status, and autonomy, (b) whether successful diabetes management during the transition into adolescence involves continued collaboration with mothers, low levels of uninvolvement, and declines in controlling involvement, (c) the process whereby collaboration produces positive and uninvolvement and control produces negative outcomes across development, (d) how fathers' involvement may either directly or indirectly affect diabetes management, and (e) broader system factors contributing to the developmental changes in appraised maternal involvement. Using a three-year longitudinal design, 200 children aged 10-14 with type 1 diabetes and their mothers and fathers will be assessed every six months. At each assessment, the constructs of developmental level, parental involvement, and diabetes adjustment will be assessed through a combination of surveys, interviews, and medical tests. In Years 1 and 3, mothers, fathers, and children will complete a two-week daily diary to examine the daily processes by which forms of appraised parental involvement affect child adjustment. The long-term goal is to identify child, parent, dyadic, and health-care provider factors that could lead to interventions to promote successful diabetes adjustment.